Many modern systems are digitally-based systems, and thus implement various digital signal processing schemes. Nonetheless, many modern systems may also include one or more analog-based circuits, to process and supply one or more analog signals. Thus, such systems may include one or more digital-to-analog converter (DAC) circuits to convert digital signals to analog signals for use by the analog-based circuits.
Numerous and varied digital signal processing schemes, as well as numerous and varied digital to analog conversion schemes, have been developed. One type of digital signal processing scheme that is used is the well-known pulse width modulation (PWM) scheme. In systems that implement the PWM scheme, when digital to analog conversion is conducted on a PWM signal that is supplied from a processor, a buffer circuit that is powered by a precision reference is provided for each PWM signal output that undergoes the digital to analog conversion. This is done so to precisely control the output amplitude of the PWM signal, and thus provide the greatest possible accuracy.
Although the use of buffer circuits, as described above, provides sufficient accuracy and is a generally reliable paradigm, there are drawbacks associated with buffer circuit use. Namely, the buffer circuits can use up valuable circuit board space and/or can increase overall circuit and system costs.
Hence, there is a need for a circuit and method for conducting PWM digital to analog conversion that does not rely on buffer circuits (or other devices) that may take up inordinate circuit board space and/or that may decrease overall circuit and system costs, as compared to presently known circuits and systems. The present invention addresses one or more of these needs.